148 



Bashford Dean tvlemorial Volume 



ASGr 



Text'figure 28. 



(Above) 



The postero-supra-gnathal plate of Dinichthys inter- 



medius Nwb.: I, from outside; II, from inside. 



F, lower part; G, attachment part; H, handle-like process; I, 



part overlapping ASG; f, front part; h, hind part with 



denticles; w, worn area. 



Text-figure 29. 



(Right) 



Union between antero-supra-gnathal (ASG) and 



postero-supra-gnathal (PSG) plates of Dinichthys 



intermedins. I, from outside; II, from inside; III, 



from above. 



The part of FSG, placed in front of this thickening, comes in contact with ASG (Text- 

 figure 28 I). One not infrequently finds VSG much broader than shown in Text'figure 28. 

 Probably the different breadth of FSG comes from age — the FSG of older examples are 

 more worn. 



As we know FSG comes in contact with SO. It touches the tongue-shaped part 

 of the handle (Text-figure 22 B) on the inside so that the upper part of the real tooth is 

 curved. The attached part thereby comes in contact with the inside of the ridge (orbital 

 wall, Text-figure 22 R;,) which runs along the upper margin of the tongue-shaped part. 

 With its front part, FSG (Text-figure 28 I) touches the surface A on ASG (Text-figure 

 27 A). The handle of PSG runs along the massive hind part of ASG. However, the attach- 

 ment between these two elements can clearly be seen from Text-figure 29. 



Infero-Gnathal. — This plate (Text-figures 30, 31 and 32; Plate VII, figures 18 and 

 19), sometimes called the mandible or the mixicoronoid (Stensio), is the real lower jaw. It is 



